Due to the worldwide increasing prevalence of the allergic rhinoconjunctivitis, new therapeutical strategies are needed. The symptomatic treatment with topical and systemic antihistamines and corticosteroids are often insufficient. E.coli Nissle 1917 has immunomodulatory capacities and reveals less side effects. E.coli Nissle 1917 has no sedative properties and exhibits no hepatotoxic qualities. Thus, E.coli Nissle 1917 represents a new relevant therapeutical agent.